Recently, an electronic clinical thermometer is practically used in place of a mercury thermometer. The electronic clinical thermometer mainly has a pencil shaped configuration, similar to the mercury thermometer. In the pencil-shaped electronic clinical thermometer, a measuring place of the human body is either under a tongue or an armpit. In either case, when the temperature is measured, the user can not look at a temperature display. Therefore, when a predetermined measuring time has passed, the electronic clinical thermometer is picked out of the measuring place so as to confirm the display. However, if a sensor head of the electronic clinical thermometer is not correctly held in the measuring place, the measurement ends in failure. Therefore, the temperature must repeatedly be measured.
Furthermore, the problems arise in the conventional electronic clinical thermometer that the user can not know whether the number indicating the temperature increases during the measurement or not, and the thermometer is in a normal state (for example, the sensor head of the electronic clinical thermometer is held in the predetermined place). Since the fact that the displayed temperature stops rising means the finishing of the measurement, the information is desirable.
In order to solve the above mentioned problems, there has been proposed an electronic clinical thermometer having a temperature calculating circuit, a data holding circuit for holding a present data obtained by the temperature calculating circuit, a comparing circuit for comparing the present data held in the data holding circuit with a newly obtained data by the temperature calculating circuit, and updating means for updating the old data with the new data. Displayed temperature data rise detecting means is provided for detecting the rise of the displayed temperature information in accordance with the updating, and for producing a temperature data rise signal. In accordance with the temperature data rise signal, sound generating means emits sounds at a constant interval to inform that the displayed temperature information is rising, and the thermometer is correctly used to the user.
Thus, in the conventional electronic clinical thermometer, since the rise of displayed temperature information is informed by the constant interval sounds, it is possible to inform to the user that the electronic clinical thermometer is correctly used during measurement. However, an elapsed time of the measurement is not informed. The elapsed time is another desirable information, because the user wants to know the present point of time in the measuring period from the beginning to end of the measurement.
In order to solve the above described problems, an object of the present invention is to provide an electronic clinical thermometer in which the user can know an elapsed time of the measurement in addition to information of displayed temperature information rising during measurement and correct use of the electronic clinical thermometer.